Patent Document 1 describes a technique of allowing solid-phase amplification of a target polynucleotide to proceed, using an oligonucleotide primer immobilized on a solid-phase support. There is further disclosed that a single-strand or double-stranded DNA, and RNA may be adoptable as the target polynucleotide, and that in particular mRNA may directly be adoptable as a template for amplification as being mediated by reverse transcription.
Patent Document 2 discloses a technique of allowing PCR reaction to proceed, by using a microplate which is stable even in a heat denaturation step of the PCR reaction, shows a small capacity of non-specific adsorption of proteins and DNA/RNA, and is durable to organic chemical substances. There is also described that, prior to the PCR reaction, by using an oligonucleotide immobilized on the surface of the microplate, RNA or mRNA may be captured from a crude cell lysate without purification.
In both of Patent Documents 1 and 2, there are described that presence of RNA in the cell lysate may be known, and that the RNA may approximately be quantified, by labeling and detecting the oligonucleotide in the process of amplification.
Specifically for this sort of RNA quantification, reverse transcription-polymerase chain reaction (RT-PCR: reverse transcriptase polymerase chain reaction) has been known to be useful. More specifically, the RT-PCR method, characterized by converting RNA into complementary DNA (cDNA) using a reverse transcriptase, and then amplifying the cDNA by the PCR method, is capable of quantitatively analyzing even a trace amount of RNA, and is now recognized as one of analytical methods having highest detection sensitivity, indispensable for detection of virus having RNA as a gene, quantitative detection of mRNA, analysis of expressive gene based on determination of base sequence, and analysis and production of expression product obtained by cloning of cDNA. The method is a very important technique in various fields including diagnostic molecular pathology.
However, the RT-PCR method is much labor-consuming in collection of cells, extraction of RNA from biological samples and purification thereof, reverse transcription reaction, PCR and gene detection, each of these steps suffers from problems of sample loss, contamination and so forth, so that the current situation is such as needing advanced skills of researchers for the purpose of stable quantification on the gene expression level. In particular, complete purification of RNA molecules is the first step determining success of RT-PCR, so that operations required therefor include removal or inactivation of ribonuclease in the cells and tissues.
To solve these problems, there have been active efforts of developing products such as automatic RNA extraction apparatus, mRNA purification kit, one-step RT-PCR reagent kit, and so forth. For example, the reagents having been used include ion exchange resin, glass filter, glass beads or those showing protein aggregating function. However, use of any of these products needs time-consuming and difficult treatment operation steps.
There has generally been used a purification-oriented technique, by which oligo dT is immobilized on the surface of the carrier, so as to capture a poly-A chain owned by mRNA. The technique was developed for the purpose of further allowing the reverse transcription reaction and the PCR reaction to proceed on the solid-phase surface (Non-Patent Document 1). However, the technique has failed in achieving a satisfactory performance, due to non-specific adsorption on the hydrophobic surface of plastic, raising problems in contamination of a protease or chaotropic reagent used for inactivating ribonuclease, and inactivation of reverse transcriptase and DNA synthase.    [Patent Document 1] Published Japanese Translation of PCT International Publication for Patent Application No. 2003-523183    [Patent Document 2] Published Japanese Translation of PCT International Publication for Patent Application No. 2002-505080    [Non-Patent Document 1] Takashi Ishikawa et al., “Construction of cDNA bank from biopsy specimens for multiple gene analysis of cancer”, Clinical Chemistry, 1997, Vol. 43, No. 5, 764